ANT COMMUNITIES 



leaves, that the site had to be abandoned. It was 

 transferred to a spot near by that was surrounded by 

 an irrigating ditch, and, thus insulated, was supposed 

 to be quite safe from emmet assault. But in course of 

 time the cutting ants appeared within the island gar- 

 den. The officers, supposing them to be the former 

 troublesome community, concluded that they had en- 

 tered by tunnelling beneath the stream. What other 

 way? But Captain Kauffman, sceptical of their ability 

 to accomplish such an engineering feat, resolved to in- 

 vestigate. He drained the irrigating stream (some four 

 or five feet wide), dug up the bed, and traced the in- 

 sects' trail from their point of entering the garden to 

 the old nest on the opposite side. The ants had in- 

 deed tunnelled beneath the water, guided unerringly by 

 their remarkable instinct in engineering. 



I have no explanation to offer of the method by which 

 the Attidie accomplished these feats in subway en- 

 gineering. The facts are given, and they are without 

 question. But by what peculiar topographical sense 

 or gift, or by what faculty or process they carried out 

 schemes which compare favorably, relative powers 

 and proportions considered, with underground roads 

 and tunnels of our own species, this author con- 

 fesses his inability even to suggest an explanation. 

 One may see how upon surface trails the antennae aid 

 in fixing the direction of the ants' course. But it is not 

 possible to see how they could aid in laying out tunnels 

 underground. 



We turn to another and widely different use of the 

 engineering faculty. In earlier days the gates of great 

 buildings and of walled towns were kept with a high 

 degree of diligence and ceremony. This was warranted 



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